Abstract : The aim of this thesis is to develop tools and procedures to study by the experimentalmicrokinetic approach, in particular for the CO-O2 reaction applied to metal supported catalystcontaining iridium particles and bimetallic Pt-Pd particles. The characterization of the first elementarystep of CO adsorption on different metals nature of adsorption, heat of adsorption of each species hasrequired the development of a method initially adapted for the IR analysis in transmission mode:AEIR method Adsorption Equilibrium InfraRed spectroscopy. The experimental conditions allowinga quantitative exploitation of IR spectra in diffuse reflectance mode has been established allowing theuse of the AEIR method. This method has been developed extending the range of application oncatalysts that dissociate strongly CO firstly using diffuse reflectance mode for catalyst which can notbe study in transmission mode Fe-Al2O3 and then in transmission mode Co-Al2O3. The impact ofparameters linked to the preparation of catalyst nature of the support, dispersion of metallic phase,and formation of bimetallic particles on the heat of adsorption has been evaluated on Ir catalysts andbimetallic particles like Pt-Pd, Pt-Cu respectively. Then, the microkinetic approach of the CO-O2reaction dedicated to Ir and Pt-Pd catalysts, considering the isothermal oxidation of CO adsorbedspecies at low temperature, has shown that the superficial steps involved were similar to those for Ptand Pd catalysts. The impacts of several experimental parameters on the oxidation of CO adsorbedspecies characterized by an induction period are qualitatively identical, only the kinetic parameterslike the apparent activation energy are modified.